Wind is faster than sound on Exoplanet HD 189733b

COVENTRY, UK – Scientists from the UK’s UniversityofWarwick reported on Friday that they have detected a windspeed of over 2Km per second (5.400 mph) on exoplanet HD 189733b. On Earth, that would be seven times the speed of sound.

The exoplanet, which was discovered in 2005, is 63 light years away from Earth or 600 trillion kilometers away. It is located in the constellation of Vulpecula, also known as “the little fox”.

Compared to Earth, they found the wind speed on the exoplanet is 20 times faster than the highest winds ever reported on our planet, including the center of any hurricane occurred here. Tropical Cyclone Olivia, occurred in 1996, remains as the fastest wind that has ever been recorded here, with wind speeds of 253 mph.

A star field image showing the star HD 189733 (centre). The NASA/ESA Hubble Space Telescope has given astronomers a fascinating new insight into the atmosphere of HD 189733b. To the right of the star is the notable planetary nebula Messier 27. The field-of-view is approximately 0.9 x 0.6 degrees. Credit:NASA, ESA, and the Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

Researchers developed the first weather map of a planet that is outside our solar system. They claim that the measurement techniques they used on planet HD 189733b could be helpful to study weather on Earth-like planets.

“Whilst we have previously known of wind on exoplanets, we have never before been able to directly measure and map a weather system”, said lead author Tom Louden, an astrophysicist at the University of Warwick.

For this study, Warwick astronomers used HARPS, which is the High Accuracy Radial velocity Planet Searcher, located in La Silla, Chile. They watched the planet as it passed right in front of its host star and detected the exorbitant speed by looking at wavelengths for atmospheric sodium, according to Louden. The scientists clarified that such a high wind speed is explained by the planet’s proximity to its parent star.
Dr. Peter Wheatley, co-author of the study, affirmed that by further developing their measurement techniques they will be able to study wind flows in more detail and map the weather of smaller planets.

In April, scientists from the Universities of Geneva and Bern informed that the temperature on planet HD 189733b reached over 3000 degrees at high altitudes in its atmosphere. The planet is almost as large as Jupiter and takes only 2.2 days to orbit its host star.

Earlier in 2007, the temperature of the distant planet was measured by NASA’s Spitzer Space Telescope. On the dayside, its atmosphere reaches nearly 3.700 degrees Fahrenheit, whereas on the night side it is 500 degrees cooler.